/*
 *  Copyright 2013 National Institute of Advanced Industrial Science and Technology
 *  
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *  
 *      http://www.apache.org/licenses/LICENSE-2.0
 *  
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */

package org.sss.mapreduce.example;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.sss.mapreduce.Output;
import org.sss.mapreduce.Reducer;
import org.sss.mapreduce.datatype.PackableInt;

public class KMeansReducer extends Reducer {
  static Logger logger = LoggerFactory.getLogger(KMeansReducer.class);

  public void reduce(Context context,
                     PackableInt key, Iterable<Center> values,
                     Output<PackableInt, Center> output) throws Exception {
    Center c = new Center();
    for (Center c0: values) {
      c.weightedVote(c0);
    }
    c.normalize();
    output.write(key, c);
  }
}
